Medicine

Abstract

Data hiding used to embed data, such as copyright information, into various forms of media such as image, audio, or text with a minimum amount of perceivable degradation to the “host” signal. Therefore, in many cases, the cover media contain distortions even after the hidden data have been extracted. Thus, to extend the application of data hiding to some sensitive domains such as military, medical, and fine arts, which require the embedded cover images to be properly covered, reversible data hiding has become another new branch of this field. Our proposed scheme is inspired by Chang et al.’s idea. In this paper, we propose adaptive real-time reversible data hiding for JPEG images using successive zero coefficients in zigzag sequences of discrete cosine transformation blocks. The contribution of our proposed scheme successfully enhances the hiding capacity while the image quality of stego image and reversibility are maintained. The result of experiments conducted indicates that the proposed scheme enhances data hiding capacity, image quality, and improves performance.

Abstract

A reversible data hiding method allows recovery of the cover image after the secret data have been extracted. In this paper, a novel reversible data hiding method is proposed using neighboring interpolation and pixel-value differencing on block expansion. A consecutive embedding technique for a sub-block is proposed to maintain a higher embedding capacity, and a neighboring pixel-value referencing is also proposed to maintain a good visual quality in stego-images. The results of experiment demonstrate that the proposed method has higher capacity and maintains a better image quality than previous reversible data hiding methods.

Abstract

shadows can reveal a vague secret image, and the black area of the secret image is recovered as perfect black. Two-in-one image secret sharing (TiOISS) scheme is a secret image sharing method with two decoding options. It can not only decode a vague secret image by stacking any k shadows, but also reveal the original grayscale secret image with k shadows by computation. Researchers proposed some TiOISS schemes, which are based on visual cryptography and polynomial-based image secret sharing (PISS). Since PISS reveals the secret image by Lagrange’s interpolation, these TiOISS schemes need complex computation. In this paper, we proposed a novel TiOISS scheme based on PBVCS using exclusive OR operation. Compared with literature TiOISS schemes, our scheme does not need complex computation in revealing process, and it can be used in real-time application. The grayscale secret image can be recovered quickly with a few Boolean operations.

Abstract

In the ubiquitous Web environment which exploits real-time image processing methods, easy access to a variety of digital contents such as movies, e-books, and digital songs significantly enhances people’s quality of life. However, most digital content sites do not provide a concrete mechanism to prohibit minors from accessing harmful content, even though a few mechanisms are available in the market to screen out minors from accessing inappropriate content. This paper proposes a fundamental approach that confirms the age of a user using his digital signature with the X.509 certificate when the user attempts to access specific digital content. Its performance is verified by the implementation of the approach.

Abstract

Since the first histogram shifting technique was proposed by Ni et al., many histogram based data hiding methods were proposed to improve their scheme. One of the methods is using difference value between cover image and prediction image. Another method is using two point pairs and absolute value for improving Ni et al.’s scheme. In this paper, novel reversible data hiding scheme with edge-direction predictor and modulo operation was proposed for improving histogram shifting technique with 3 cases. We considered as much as possible around pixels by using edge-direction predictor with odd and even line embedding Also, we utilize two point pairs and absolute value at the same time by using modulo operation with wrap around. In the experimental results, the proposed scheme shown a good quality image result about 48dB as similar as other schemes and enhanced hiding capacity over 50 % than other schemes.

Abstract

With the development of steganography, it is required to build high-dimensional feature spaces to detect those sophisticated steganographic schemes. However, the huge time cost prevents the practical deployment of high-dimensional features for steganalysis. SRM and DCTR are important steganalysis feature sets in spatial domain and JPEG domain, respectively. It is necessary to accelerate the extraction of DCTR and SRM to make them more usable in practice, especially for some real-time applications. In this paper, both DCTR and SRM are implemented on the GPU device to exploit the parallel power of the GPU and some optimization methods are presented. For implementation of DCTR, we first utilize the separability and symmetry of two-dimensional discrete cosine transform in decompression and convolution. Then, in order to make phase-aware histograms favorable for parallel GPU processing, we convert them into ordinary 256-dimensional histograms. For SRM, in computing residuals, we specify the computation sequence and spilt the inseparable two-dimensional kernel into several row vectors. When computing the four-dimensional co-occurrences, we convert them into one-dimensional histograms which are more suitable for parallel computing. The experimental results show that the proposed methods can greatly accelerate the extraction of DCTR and SRM, especially for images of large size. Our methods can be applied to the real-time steganalysis system.

Abstract

In this paper, a steganographic method for real-time data hiding is proposed. The main goal of the research is to develop steganographic method with increased robustness to unintentional image processing attacks. In addition, we prove the validity of the method in real-time applications. The method is based on a discrete cosine transform (DCT) where the values of a DCT coefficients are modified in order to hide data. This modification is invisible to a human observer. We further the investigation by implementing the proposed method using different target architectures and analyze their performance. Results show that the proposed method is very robust to image compression, scaling and blurring. In addition, modification of the image is imperceptible even though the number of embedded bits is high. The steganalysis of the method shows that the detection of the modification of the image is unreliable for a lower relative payload size embedded. Analysis of OpenCL implementation of the proposed method on four different target architectures shows considerable speedups.